THURSDAY, March 22 (HealthDay News) -- Teachers and parents play a greater role than peers in keeping teens engaged in school, researchers have found.

The findings challenge the widely held belief that peers have the greatest impact on the lives of adolescents, according to a report from the University of Michigan.

For the study, the investigators analyzed data from nearly 1,500 students from 23 schools in the Washington, D.C., area who were interviewed when they were in 7th, 9th and 11th grades. The questions asked by the researchers focused on four indicators of student engagement: compliance with school rules, participation in extracurricular activities, identification with their school and the value placed on education.

The students also were asked about the support they received from teachers, parents and peers.

As expected, the students' school engagement decreased over the years and the decline was more steep among boys than among girls, according to the report, which is published in the current issue of the journal Child Development.

The researchers also found, however, that students' school engagement was just as likely to be positively affected as negatively affected by their peers.

In addition, the results indicated that any negative influences from peers could be counteracted by social support from adults, and from teachers in particular. This support included encouraging student engagement, stressing the importance of obtaining an education, and making it easier for students to take part in extracurricular activities.

"We were surprised to find that most adolescents continue to be influenced greatly by their teachers and parents when it comes to school engagement," study author Ming-Te Wang, a faculty research fellow at the University of Michigan Institute for Social Research, said in a university news release.

"Even though this is a stage when young people are moving toward establishing autonomy and independence, teachers and parents remain important in helping them stay involved in school, and in extracurricular activities," Wang said. "And this is true for all ethnic groups and races, and across all the economic groups we studied."

"Adolescence is a period when relationships with adults who aren't your parents become increasingly important," Wang added. "Our results suggest that supportive teachers play a particularly important role in keeping teens engaged in school."